This invention relates to facing materials for products for absorbing body exudate and in particular, relates to facing materials for sanitary napkins whereby, after the napkin has absorbed body fluid, the facing material presents a relatively clean and dry appearance.
Absorbent products for absorbing body exudate and sanitary napkins in particular all generally comprise a body facing side, for application against the body and through which body exudate will flow; an absorbent core, for absorbing and retaining such body fluid; and a garment facing side, generally worn against the inside crotch portion of an undergarment. Usually the body facing side of the napkin comprises a sheet of body fluid pervious facing material and the garment facing side of the napkin comprises a body fluid barrier material. In some cases the sheet of which the body facing material is comprised extends completely around the product and overlies the barrier material.
Recently sheet materials for the body fluid pervious facings have been selected not only to be pervious to body fluid, but also not wettable by such fluid i.e., hydrophobic. Such hydrophobic facing materials have several well known advantages in that they remain relatively dry and hence are more comfortable in use. Additionally, by not wetting, they remain free of stain on their exterior surface. Accordingly, the art is now replete with suggestion for utilizing hydrophobic facings in body fluid absorbent products. For example in U.S. Pat. Nos. 3,695,269; 4,041,951; and 4,391,869; it has been suggested that nonwoven fabrics comprised of hydrophobic fibers be employed as the facing on absorbent products. In U.S. Pat. Nos. 2,992,644; 3,814,101; and 4,324,246; it is suggested that the facing comprise a continuous sheet of hydrophobic polymeric material, rendered permeable to body fluid by being provided with apertures.
While in the main, such hydrophobic facing materials have performed their function of allowing for the passage of body fluid therethrough without staining or wetting, it has been discovered that the user is still left with the uncomfortable perception that the facing is stained. This somewhat anomalous situation appears to be a result of the fact that notwithstanding the nonwetting, nonstaining properties of the materials from which the facing is made, the absorbent material underlying the facing clearly is stained, as it must be to function, and the stains on these underlying surfaces are visible to the user through the facing. This situation is particularly aggravated in the case of sanitary napkins wherein the stain is dark colored and is highly visible through the heretofore suggested facing materials.
Accordingly, there is a need for providing a facing material which not only can perform the desirable functions of allowing body fluid to be transmitted to the absorbent core of the product without wetting or staining the facing, but will also give the appearance of being clean and dry, thus providing the user with peace of mind.